Titlebook: MRI Physics for Physicians; Alfred L. Horowitz Textbook 19891st edition Springer-Verlag New York Inc. 1989 Magnetic field.Radiologists.ele

Living-Will

薄荷醇

Relaxation,We are now ready to embark upon part three of MR.: relaxation. Remember that the RF pulse is exactly that: a, .. It is applied for only a brief period of time, and then it is shut off.

Blasphemy

T2 and the Spin-Echo Pulse Cycle,In preceding chapters, we glibly referred to the T2 decay of the Bl vector after application of the RF pulse. Actually, we oversimplified the case in order not to obscure the understanding of the relationship of T1 and T2 to TR and TE. But now, it is time to delve more deeply into what T2 actually is.

錫箔紙

欺騙世家

Frequency Gradient,So far, we have shown how we select an image plane, which represents only the first of the three coordinates that we must specify. To complete our image, we must understand how the other two orthogonal gradients specify the other two coordinates of each point in a given plane.

異端邪說下

The Fourier Transform,We will eventually show that a Fourier transform is a spectrum. Hence it is necessary to know what a spectrum is.

Jogging

說笑

Gradients,how these different intensities are arranged in space to produce an image. There are a number of ways of doing this, but we will be concerned only with the most widely used method: two dimensional Fourier transform (“2DFT”) reconstruction.

Lethargic

監(jiān)禁